I just put a new clutch in my van,now it won't engage.You push the pedal in and nothing happens, What has gone wrong.Any ideas.     
Thanks in advance.

Cable adjusted properly?

I changed the clutch recently when converting to a 5 speed... There was a little metal spacer about 10mm cubed which I think went in before the clutch fork to make a bigger action in it... It was odd because the donor gearbox which had the bellhousing and fork connected did not have it. When I installed it without the spacer it had the same symptom.

The spacer is only for Pinto's. If the box was previously behind a Kent motor the block wont be there.  However in this case i would assume he has refitted the same gearbox when replacing the clutch?

Get a friend to sit in the car and operate the clutch while you're looking underneath to see what the clutch fork is doing. If the cable is properly adjusted (~ 3mm freeplay) and on depressing the clutch fully the arm hits the edge of the opening then you will need that spacer block. 
Is it a sierra T9 5 speed with cast iron B/H, alloy RS2000 type , Masport alloy one. Or a Toyota 5 speed with Dellow B/H ?
Silly question  but I have to ask, bellhousing bolts done up?
 
rgds,
SFE